Hydrolysis of Me3SiCH2 groups on a double-chelating bis(ferrocenediyl)diphosphine coordinating to a Pt(0) center

The double-chelating diphosphine ligand PCH2SiMe3-bridged [1.1]ferrocenophane (1), in which two phosphorus donor atoms are doubly linked with two ferrocene groups and with a Me3SiCH2 group on each phosphorus center, was reacted with [Pt(PPh3)3] to form the tricoordinated Pt(0) complex [Pt(1)(PPh3)]. Refluxing of this complex with another equivalent of 1 in THF inadvertently containing traces of water was found to successively hydrolyze the four Me3SiCH2 groups of [Pt(1)2] to eventually form [Pt(2)2], in which all the initial Me3Si groups of [Pt(1)2] were replaced with hydrogens. The molecular structure of [Pt(2)2], as determined by X-ray analysis, shows stereochemical congestion between the two ligands. Since hydrolysis in refluxing THF did not proceed at all for both the free ligand 1 and the Pt(II) complex [PtCl2(1)], the stereochemical congestion of the Pt(0) complexes having two double-chelating diphosphine ligands is probably responsible for the observed hydrolysis.

The double-chelating diphosphine ligand, having a Me3SiCH2 group on each phosphorus center, was refluxed in the presence of a Pt(0) complex in wet THF, resulting in the hydrolysis of the Me3SiCH2 groups.Figure optionsDownload as PowerPoint slide